string(250) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%8D%A1%E5%B0%94%E6%9B%BC%E6%BB%A4%E6%B3%A2%E7%AE%97%E6%B3%95c%E8%AF%AD%E8%A8%80 => Failed to connect to 101.89.166.210 port 38089: Connection refused"
卡尔曼滤波算法c语言
